A year ago I installed a free e-mail certificate that has expired. What I didn’t realize then - it’s only valid for a year. So if someone I sent e-mail over the past year opens one of those e-mails, he or she is presented a message there’s a problem with the signature. The problem being an expired certificate. So instead of introducing more secure e-mail by using a certificate, I created e-mails that look suspicious when that certificate expires. Not exactly what I had in mind. E-mail certificates sold by Comodo are only valid at best 3 years. So that’s no solution and I have to think of another way to sign e-mails.
But for those e-mails sent - I guess there’s no way for me to present them to the receiver as valid indefinitely?
Simon